#! /usr/bin/ruby

unless ARGV.length == 2
puts "Usage: ruby my-diff.rb oldfile newfile"
exit
end

def trans_to_downcase (filename)

	File.open(filename).collect {|line| line.downcase}
end

old_array = trans_to_downcase (ARGV[0])
new_array = trans_to_downcase (ARGV[1])

puts "new added files are as below:"

puts ""

puts new_array - old_array

puts "============================="

puts "removed files are as below:"

puts ""

puts old_array - new_array

